The phagocytic capacity of neurones.

Phagocytosis is defined as the ingestion of particulates over 0.5 microm in diameter and is associated with cells of the immune system such as macrophages or monocytes. Neurones are not generally recognized to be phagocytic.

Distribution of GAP-43, beta-III tubulin and F-actin in developing and regenerating axons and their growth cones in vitro, following neurotrophin treatment.

Brain derived neurotrophic factor (BDNF) when added to explant cultures of both embryonic and adult retinal ganglion cell (RGC) axons exerted a marked effect on their growth cone size and complexity and also on the intensity of GAP-43, beta-III tubulin and F-actin immunoreaction product in their axons. GAP-43 was distributed in axons, lamellipodia, and filopodia whereas beta-III tubulin was distributed along the length of developing and adult regenerating axons and also in the C-domain of their growth cones. BDNF-treated developing RGC growth cones were larger and displayed increased numbers of GAP-43 and microtubule-containing branches.

The outgrowth response of the axons of developing and regenerating rat retinal ganglion cells in vitro to neurotrophin treatment.

BDNF and NT-4 (but not NT-3 or CNTF) significantly enhanced the outgrowth of early embryonic and adult regenerating RGC axons when provided with a supportive substrate in vitro. BDNF and NT-4 treatment transiently increased RGC axon outgrowth from E15 rat retinas but not from retinas at older embryonic ages. The transient effect of BDNF and NT-4 and the inability of the neurotrophins to promote outgrowth from older embryonic retinal explants suggests a time frame of neurotrophin action and that other chemical factors (target-derived or otherwise) may be necessary for the continued maintenance of developing RGC axons.

Effects of microinjected small GTPases on the actin cytoskeleton of human neutrophils.

This paper describes a method for microinjection of proteins (Rho GTPases) into neutrophils and observations on the responses of the cells to these injections. Neutrophils are extremely difficult to inject because of their small size, complex morphology and fragility. To allow microinjections they must be cultured on a substrate that enables them to settle, adhere and spread.